These Are the Fastest Creatures on Earth But You'll Never Spot Them

Spirostomum ambiguumSpirostomum ambiguum, s. ambiguum
Spirostomum ambiguum specimens, each about 4 millimeters long in its expanded state, look wormlike under a microscope.
(Image credit: Rob Felt, Georgia Tech)

Scientists have a plan to study the fastest creature in the world — and hope to use what they learn from its behavior to build tiny robots.

The creature isn't a cheetah or a falcon; instead, it's a single-celled organism called Spirostomum ambiguum, commonly found in bodies of water. Cheetahs can sprintat speeds of more than 60 mph (96.5 km/h), and falcons may dive at well over 250 mph (400 km/h). But S. ambiguum can move even faster, shortening its body by 60 percent into a football shape within "a few milliseconds," according to a press release.

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Rafi Letzter
Staff Writer
Rafi joined Live Science in 2017. He has a bachelor's degree in journalism from Northwestern University’s Medill School of journalism. You can find his past science reporting at Inverse, Business Insider and Popular Science, and his past photojournalism on the Flash90 wire service and in the pages of The Courier Post of southern New Jersey.